U.S. Pat. No. 4,927,136 discloses an electromechanical and more particularly an electromagnetic brake that is utilized in the control of exercise equipment, including escalator-type stair-climbing apparatus in which electronically controllable torque, including a clamping torque, is applied to a rotary shaft to load the exercise equipment, thereby giving complete electronic control to the operation of the exercise apparatus, including a safety locking function.
U.S. Pat. No. 5,120,050 discloses a step-type exerciser that has an endless loop of steps in which each step has an associated pair of pulleys, one at each end, and these run on fixed “inside out” Vee belts. Drive is transmitted by toothed pinion blocks carried adjacent to each roller but angularly fixed whereas the rollers are rotatable, and the blocks engage a second belt which is driven by a motor.
U.S. Pat. No. 5,145,475 discloses an exerciser that provides low impact exercise for the upper and lower body of an operator. The apparatus includes an upper portion having moving rungs simulating a hand-over-hand motion to exercise one's upper body and a lower portion having moving platforms simulating a stair-like climbing motion to exercise one's lower body. The upper and lower portions are oriented at different angles to maximize operator comfort, the angle of the lower portion in particular providing clearance for one's knees during use. The exerciser also includes a variable speed control to adjustable vary the speed of the moving rungs and platforms, thereby adapting to the needs of various operators.
U.S. Pat. No. 5,328,420 discloses a stair step exerciser that is mounted on a frame having horizontal and vertical components. A carriage comprised of a pair of side plates is pivoted to one end of a horizontal component and is retained at the other end in one of a series of vertical stops to selectively determine the angle of the carriage with respect to the frame. The carriage has pulleys at both ends which support the belts on which treads are pivoted at one end. The other end of the treads rest on one rail of a four bar linkage, which linkage expands as the carriage angle is decreased and collapses as the carriage angle is increased so as to always maintain the treads horizontal. A pair of hand cables is provided which move at substantially the same speed as the treads. The hand cables are mounted so as to be closer to the treads as the angle of the carriage increases and so as to move away from the treads as the angle of the carriage decreases.
U.S. Pat. No. 5,556,352 discloses a stair exerciser having a plurality of revolvable steps supported by endless chain conveyors and a control device for speed control, which, by the weight and action of a operator walking on the steps, enables the mechanism to run cyclical and continuous action thereby affording the operator stair climbing like exercises.
U.S. Pat. No. 5,769,759 discloses an apparatus for simulating stair climbing which allows selection of step height. A side member is pivotally mounted to a base and oriented at a selected angle with respect to the base. A displacement mechanism mounted to the base is attached to the side member for rotating the side member with respect to the base. A series of platforms travels in a selected platform path including along the side member. The top surface of each platform is a predetermined horizontal distance from the top surface of an adjacent platform which corresponds to the selected angle.